Whatever other rationales are offered up for why NATO remains relevant,
it's central, animating purpose is to keep America immersed in the
affairs of Europe. Seen in this light, Europe's collective decision to
continue to sacrifice defense budgets on the altar of austerity is a
feature, not a bug.

The logic at the time of the fall of the Soviet Union, in both Washington and Europe -- including, significantly, in Paris -- was that a continued American presence in Europe was essential to guarantee a stable transition. Back then, remember, reuniting the two Germanies was an anxiety-causing proposition, let alone the idea of integrating all of the former Warsaw Pact countries into what was not yet even the European Union, but the European Communities (until 1993). So the mature institutional structure of NATO and the American commitment it represented was a welcome insurance policy, and one whose dividends paid off in the Balkans and Kosovo.

Of course, as the Soviet threat and the instability of the immediate post-Soviet European environment recedes further into the historical past, it's easier to question whether NATO remains relevant, as Stephen Walt does here, or even effective, as David Ucko does here.

I agree that those questions, on a theoretical level, are worth pursuing, and it's not a coincidence that they drove the adoption of the out-of-area mission in the alliance's last Strategic Concept, due to be updated this November.

But I think they miss the essential explanation behind NATO's endurance, which has less to do with whether it's relevant, and more to do with the fact that it remains useful, for all parties involved. For Europe, and especially the smaller member states, the obvious reason is that it allows savings in defense spending. It also affords training and interoperability opportunities with U.S. forces, as well as access to pooled assets, with the most important of these being the coolective nuclear deterrent. There are some drawbacks for the larger European states, and especially those with hopes of maintaining autonomous defense industries -- and policies. But even for them, the advantages outnumber the drawbacks.

The case is harder to make for the U.S. side of the ledger, but here, too, I think there are a lot of advantages the alliance offers the current U.S. defense posture that are often overlooked. To begin with, the U.S. strategic interest in Eastern Europe and the Caucasus as a hedge against resurgent Russian expansionism would have been impossible without NATO, and would be much more destabilizing were it to be shifted to a strictly bilateral basis, as the Bush-administration BMD proposal demonstrated. Also, the nascent U.S. presence in Central Asia would face exponentially greater logistical complications were it not for advanced staging bases in Europe. The same goes for the current war effort in Afghanistan.

Finally, and perhaps most overlooked and most under-appreciated, the U.S. strategic interest in Africa is currently dependent on a presence in Europe, as the AFRICOM headquarters has not been able to find a permanent base structure on the continent itself.

In other words, NATO has outlived its initial function as a security guarantee for Europe, and has now become essentially the same kind of rent arrangement we've established in Central Asia, with the higher fee reflecting the greater long-term value of the real estate we occupy. That, and not any real security relevance, is what sustains the alliance today.

Without putting words in his mouth, I suspect that Walt might be as
lukewarm to these practical applications as he is to the alliance
itself. I'm not very enthusiastic about some of them myself. But not
only do they bear
noting, they need to be addressed if any critique of NATO hopes to have an
impact.